The invention relates to a device for measuring pressure acting on a support, the device having at least one sealed bag filled with a fluid and having flexible bag walls to which there is connected a flexible capillary tube. The flexible capillary tube has a free end which is connected to an evaluation device which detects a pressure variation.
It is known to carry out pressure measurement using electronic sensors which convert a pressure exerted on the sensor into an electrical signal which, after amplification, if necessary, can be transmitted via electric lines to an evaluation device. Such sensors cannot be used in every case, since they have solid housings. Moreover, these sensors are relatively sensitive.
For example, it is not possible using the known sensors to measure the pressure exerted by a person on a sitting surface or lying surface, largely free of error over the entire surface, because the sensors have a disturbing effect on the pressure distribution because of their solid housings.
With particular regard to the measurement of high pressures, it is known from DE-C- 882,619 and from DE 2,550,718 Al to deform a liquid-filled cushion or a liquid-filled box and to relay the increase in internal pressure thereby produced to a measuring instrument via a flexible capillary tube.
Such arrangements are clearly not suitable for measuring the pressure exerted by a person on a sitting surface or a lying surface.
It is known in principle from DE 3,625,098 Al to measure the deformation of a diaphragm deformed by pressure in an optical fashion with the aid of two optical fibers. The optical fibers are arranged in this case on the side of the diaphragm not subjected to pressure.